#89 Support more metadata from ISO image

[Jorgo]

This pertains to the SACD ISO patcher software https://sourceforge.net/p/sacddecoder/discussion/1844612/thread/4360605374/
which I've used extensively lately.

I've had some long discussions with the developer about how metadata is written and pulled by foobar2000. Turns out, that "album artist" is never filled, only "artist". Of course, with a sidecar .xml one can then tag the ISO however one wants.

It would be great, though, if the native fields present in an SACD ISO image could already presented by foobar2000 in an optimised way. If you use the SACD ISO patcher software - which is basically an authoring software - you will see the fields that can be edited are "Album Artist" and "Disc Artist".

In foobar2000, the sacddecoder plugin currently maps these fields as follows:

"Album Artist" => "artist"
"Album title" => "album"
"Disc Artist" => dropped
"Disc Title" => dropped

In my opinion it would be desirable to map as follows instead:

"Album Artist" => "album artist"
"Album title" => "album"
"Disc Artist" => "artist"
"Disc Title" => "discsubtitle"

Thanks for considering!

[Maxim V.Anisiutkin]

"discsubtitle" is not a kind of standard meta tag. Will it be ok to have <DISCSUBTITLE> entry on the metadata tag list?

[Jorgo]

That was just an idea I had, I think that would work in fb2k - I'll gladly test anything you come up with!